Various mining and well drilling operations utilize a variety of drilling assemblies, wherein those assemblies comprise a plurality of cutting bits, in combination with and one or more nozzle devices, disposed in a complex housing assembly. Such drilling assemblies, including the arrangement of cutting bits and nozzle devices, are custom-made for specific drilling applications. In certain embodiments, each of the plurality of cutting bits and nozzle devices are removeably disposed in the housing assembly, thereby allowing replacement of used/damaged cutting bits and nozzles.
Such drilling apparatus housing assemblies are formed using a metal, ceramic, or cermet casting process. During that process, a plurality of nozzle device displacements, and a plurality of drilling bit displacements, are inserted into a casting mold. After the housing is cast, those displacements are removed from the housing thereby leaving cavities in which nozzle devices and/or cutting bits are later inserted.
Using prior art methods, such nozzle device displacements and cutting bit displacements comprise graphite, and are formed by machining graphite rods. Exposure of the graphite displacements to the temperatures and pressures of the metal, ceramic, or cermet casting process, and the forces used to remove those displacements from the cast part, generally destroy those graphite displacements. In addition to destroying the graphite displacements, an inordinate amount of time is required to completely remove each and every graphite displacement from the cast part.